This disclosure concerns an invention relating generally to components for mechanized/automated actuation of valves, and more specifically to components for coupling valves to pneumatic, hydraulic, electromagnetic, or other forms of actuators whereby the valves may be remotely actuated.
Manually-actuated valves, which are actuated by grasping their handles and rotating them to turn their valve stems and thereby modify fluid flow through the valve, are well known. It is often desirable to modify manually-actuated valves so that they may be remotely or automatically actuated by some type of industrial actuator, e.g., a pneumatic actuator, hydraulic actuator, electromagnetic actuator, or other form of actuator providing a rotary input. When valves are modified in this manner, the valve handle is removed from the valve stem, and the valve stem is then connected to an actuator shaft, or to a transmission shaft extending between the actuator shaft and valve stem. The actuators are generally small components with trailing hoses or wires, and they need to be anchored to some portion of the valve or its environment so that rotation of the actuator shaft provides a positive torque input to the valve. Without such anchoring, rotation of the actuator shaft will merely cause the actuator to spin about the valve stem when it is actuated. Rather than building some form of expensive and space-consuming supporting framework which affixes the actuator to the valve""s environment, it is usually preferable to somehow affix the housing of the actuator to the housing of the valve so that the actuator and valve are held in fixed relation when the actuator shaft communicates torque to the valve stem.
However, problems commonly arise when attempts are made to couple actuators to valves in this manner. Valves are generally not specifically designed for coupling to valves, and they have a wide variety of sizes and shapes, making it difficult to develop an off-the-shelf coupling solution. Actuators generally do not have such a wide variety of possible configurations and are thus less problematic than valves, but they are nonetheless problematic as well. The actuator and valve housings can sometimes be welded together (or a bridge can be welded therebetween), or other permanent forms of affixation can be used, but these measures are not preferred because of the difficulty in later repair and replacement of the valve and/or the actuator, and also because of the potential damage that may occur to most common actuators if welding is used.
The step that is most commonly taken to achieve a removable affixation between an actuator and a valve is to provide a structure generically known as a xe2x80x9ccouplerxe2x80x9d between the actuator and the valve, with the coupler being configured to join certain categories of valves to certain categories of actuators and serve as a bridge therebetween. Examples of couplers of this nature are seen in U.S. Pat. No. 4,633,897 to Effenberger, 4,719,939 to Killian, U.S. Pat. No. 4,887,634 to Killian, U.S. Pat. No. 5,240,030 to Wang, U.S. Pat. No. 5,564,461 to Raymond, Jr. et al., U.S. Pat. No. 5,634,486 to Hatting et al., U.S. Pat. No. 5,927,682 to Gul et al., U.S. Pat. No. 5,954,088 to Huang, U.S. Pat. No.6,135,417 to Wadsworth et al. and Japanese Patent No. JP406066327A to Yabanetta.
However, these couplers are subject to several disadvantages. First, a coupler""s primary goal is to rigidly fix the valve housing with respect to the actuator housing, while mechanically linking the valve stem to the actuator shaft to allow torque transmittal. However, the attachment of the valve and actuator housings often tends to cause problems with torque transmittal because it introduces misalignment between the axes of the valve stem and actuator shaft. If any eccentricity and/or pitch is present between the axes of the valve stem and actuator shaft, the components will experience significant stress and will quickly wear with repeated actuation. Even where couplers have been specifically designed to join particular makes and models of valves and actuators, this misalignment can occur owing to imprecision in aligning the valve stem and actuator shaft. Such imprecision is amplified by imprecisions in valve manufacture, since common valves are manufactured with a surprisingly high degree of variability from valve to valve, thus making it difficult for one coupler to properly fit all valves. For example, it is not uncommon to see variances of up to 5 degrees or more, as measured between the mounting plate of a valve and its valve stem, between the valve stem axes of different valves in a manufacturing run. This variability does not reflect poor quality manufacture, but rather reflects that the valve was intended for manual actuation and flow control. Thus, once the valve packings are installed so that proper valve performance is attained, the valve is suitable for use, and there is no need for its manufacturer to concentrate on its appearance, or its uniformity with other valves in the manufacturing run (or risk the valve""s performance by attempting to improve these features). Since the valve will (presumably) be manually actuated, and manual actuation can readily accommodate any irregularity in valve stem orientation, such irregularity is not an important issuexe2x80x94unless the valve is modified for automatic actuation.
Second, where bolt holes are provided on valves and actuators for mounting, the bolt hole placement tends to be different between different manufacturers, makes, and models (though some standard hole placements exist for actuators). Thus, different couplers with different bolt hole placements are needed for each possible valve/actuator combination.
Third, most prior couplers introduce substantial space between the valve and actuator. This is generally necessary so that the coupler can be properly mounted between the valve and actuator, though it can sometimes be useful to allow a flexible transmission shaft to be inserted between the valve stem and actuator shaft to relieve the stress caused by misalignment of their axes. However, the increased space required by these couplers can be undesirable since actuators and couplers must often work in conditions of limited space.
To overcome the foregoing problems, the approach most commonly taken is to take a piece of rectangular tubing, drill holes in its opposing sides which are suitable to allow affixation of the valve and actuator to the opposite sides, and then machine a central shaft/stem bore between the opposing sides so that the actuator shaft, valve stem, and/or transmission shaft can extend between the valve and actuator within the shaft/stem bore. A coupler somewhat similar to this arrangement is seen in U.S. Pat. No. 4,633,897. Since each coupler is custom-made, it is naturally compatible with whatever proposed valve and actuator configurations are in issue, and its maker can fashion it so that it readily accommodates any manufacturing irregularities. However, it is inconvenient to have to rely on the custom generation of couplers each time one is desired. Custom generation is time-consuming, and requires that one maintain an inventory of rectangular tube stock for use in making couplers.
Thus, it would be desirable to have couplers available which do not require custom manufacture, and which may simply be pulled off the shelf to accommodate whatever valve and actuator pair that is proposed for coupling. Ideally, such a coupler would be compact and would not space the actuator so far away from the valve that use of the coupler in confined environments is effectively precluded. Additionally, it would be useful if such a coupler would at least partially compensate for the problem of shaft misalignment between the valve stem and actuator shaft, and the stress and wear that such misalignment can cause on the actuator and valve.
The invention involves a coupler which is intended to at least partially solve the aforementioned problems. To give the reader a basic understanding of some of the advantageous features of the invention, following is a brief summary of preferred versions of the coupler. As this is merely a summary, it should be understood that more details regarding the preferred versions may be found in the Detailed Description set forth elsewhere in this document. The claims set forth at the end of this document then define the various versions of the invention in which exclusive rights are secured.
Preferred versions of the coupler are intended to couple standard actuators, which have actuator mounting holes defined therein about an actuator shaft, to standard valves, which include valve mounting holes defined therein about a valve stem. Preferred couplers include an actuator mounting side and an opposing valve mounting side, wherein the actuator mounting side is adapted to mount a selected actuator thereon and the valve mounting side is adapted to mount a selected valve thereon. A series of actuator affixment holes extend into the actuator mounting side, with the actuator affixment holes being arrayed identically to actuator mounting holes defined in the selected actuator, thereby allowing fasteners to extend from the actuator affixment holes to the actuator mounting holes of the selected actuator and affix the selected actuator to the actuator mounting side. Similarly, a series of valve affixment holes extend into the valve mounting side, with the valve affixment holes being arrayed identically to valve mounting holes defined in the selected valve so that fasteners may extend from the valve affixment holes to the valve mounting holes of the selected valve and affix the selected valve to the valve mounting side. A shaft/stem bore also extends between the mounting sides to accommodate a valve stem, actuator shaft, and/or transmission shaft whereby torque may be transmitted from the selected actuator to the selected valve. To allow the coupler to effectively become xe2x80x9cuniversalxe2x80x9d so that it may affix to valves and/or actuators other than the selected valve and actuator, a series of surplus affixment holes extend into one or more of the actuator mounting side and the valve mounting side, with the surplus affixment holes being arrayed differently than the actuator mounting holes of the selected actuator and the valve mounting holes of the selected valve. These surplus affixment holes are spaced from the actuator affixment holes and the valve affixment holes, and are arrayed identically to at least one of actuator mounting holes defined in an actuator other than the selected actuator, and valve mounting holes defined in a valve other than the selected valve. Thus, the coupler may be fastened between different sets of actuators and valves. To do so, one or more of the selected actuator and the selected valve are removed from one of the mounting sides to allow a second actuator or second valve to affix to the same mounting side in its place, with the second actuator or second valve being affixed to this mounting side by fasteners extending into the surplus affixment holes.
When a coupler is used to affix an actuator to a valve in the aforementioned manner, the valve stem, actuator shaft, and/or transmission shaft of the valve and actuator extend through the shaft/stem bore to transmit torque from the actuator to the valve. To reduce the distance between the actuator and valve and thereby reduce the effects of valve stem and actuator shaft misalignment, cavities may be formed in at least one of the mounting sides of the coupler to receive a portion of the valve or actuator therein (for example, a boss protruding from the valve) when the valve and actuator are affixed to the coupler. The valve or actuator will therefore be partially received within the coupler to allow it to rest closer to its opposing actuator or valve. Preferably, these cavities are formed in at least one of the mounting sides of the coupler, and extend partway between the mounting sides of the coupler. These cavities are preferably defined by one or more slots, since bosses protruding from valves and/or couplers are often defined by one or more protruding elongated bars. Additionally, the cavities preferably extend from and open onto the shaft/stem bore, since bosses protruding from valves and/or couplers are generally located adjacent the valve stem and/or actuator shaft. Apart from allowing closer coupling of the valve and actuator, such cavities are also beneficial in that they can be formed to complementarily receive any bosses protruding from valves and/or couplers, and the interfitting relationship between the bosses and the cavities can assist in preventing relative rotation between the valve and actuator when the actuator shaft transmits torque to the valve stem.
Couplers having the foregoing characteristics need not be formed as single-piece units, and may instead be formed as a pair of coupler sections. In this version of the invention, a user is preferably provided with a number of coupler sections. Each coupler section may include one of the aforementioned mounting sides, and may also include an opposing juncture side having juncture fastening holes formed therein. The juncture side of each of the coupler sections is contoured so that it may abut the juncture side of one of the other coupler sections with the coupler sections having aligned juncture fastener holes, thereby allowing the coupler sections to be fastened together by inserting fasteners through their juncture fastener holes. The coupler sections may be formed in such a manner that they are identical save for their affixment holes, i.e., the affixment holes of the coupler sections may be differently sized and shaped between the various coupler sections, so that each coupler section can be affixed to different sets of actuators and valves. Thus, to construct a coupler which may affix a selected actuator to a selected valve, the user need simply select a first coupler section having affixment holes suitable for fastening the first coupler section to the selected actuator, and a second coupler section having affixment holes suitable for fastening the second coupler section to the selected valve. After each coupler section is affixed to its actuator or valve, the coupler sections may then be fastened together at their juncture fastening holes to thereby complete the assembly of the coupler (and thereby couple the actuator and valve).
Since the versions of the coupler which utilize a pair of coupler sections require that the coupler sections be fastened together at their juncture sides after their affixment sides are fastened to the valve and actuator, the juncture fastening holes are preferably defined on flanges extending from the juncture side of each coupler section so as to provide greater working room and clearance for accommodating fasteners. Similarly, it is preferable to define flanges on the mounting sides of each coupler section, and define the affixment holes in these flanges. Any flanges on the mounting side are preferably defined in planes spaced from any flanges on the juncture side, with the axes of the affixment holes having their axes spaced from the axes of the juncture fastening holes.